I have run long form informercials and short from radio (both :60 ad :120).
in terms of the cable company doing the ad, I have found I normally get what I pay for when it comes to creative.
If you have some example ads they can knock off, then it may work.
Most importantly, it is only $1500.
If you want to get into DR TV, Radio, or Print with mass market products (debt, diet, ringtones, etc.) then you have to look at the remnant space.
In a lot of ways, i find tuning content network ads and remnant media ads very similar. You have to be willing to test to find out what works, and then start dropping the losers and ramping the winners.
Just remember not to read too much into whatever the results are. That amount of media will serve as a good test. And, at the end of the day you will know something about that offer/channel/timeslot/time of year/creative only. Any change in those variables could yield different results.